Answer:
Oxygen is a reactant of cellular respiration, while being the product for photosynthesis
Explanation:
Photosynthesis
carbon + water + sunlight -> oxygen and glucose
Cellular respiration
oxygen + glucose -> carbon + water + ATP
Closed system. If the system is not closed, matter or energy can escape from the system. an example of this is if you react magnesium and hydrochloric acid in a open system. The H₂ gas is going to escape making it look like some of the mass disappeared . in that same reaction some in an open system will also loose heat to the surrounding which will make it look like less heat was produced.
Answer: 15.3 grams C
Explanation: 1 mole is 6.02x10^23 atoms. We can find the moles of C in 7.675 x 10^23 atoms of C by dividing:
(7.675 x 10^23 atoms C)/(6.02x10^23 atoms C/mole) = 1.275 moles C
The molar mass of carbon is 12g/mole. So the mass of 7.675 x 10^23 atoms is (1.275 moles C)*(12 g/mole C) = 15.3 grams.